Core A (Vector 1) will provide assistance in the design, construction and struCtural verification of gene therapy vectors based on adenovirus (Ad), adeno-associated virus (AAV), herpes simplex virus I (HSV). The major role of the core is to provide knowledge and biological materials to the investigators so they may focus on the biological aspects of their projects rather than the technology of gene therapy. For this reason the core will fulfill the following roles: Perform large scale vector preparations for the participating projects (target 50 preparations /year) in accordance with the core usage allocations and resources available; Create new gene therapy vectors by importing improvements in the technology and / or new transgenes that are important for the participating projects (target 18 / year); Provide Standard Operating Procedures for all phases in the construction of all three types of viral vector; Education in construction of vectors through tutorials with senior core scientists and shadowing core technicians; Supply verified samples of biological materials for the vector construction including plasmids, cell lines and starting vectors, and maintain a database describing those materials.